Corrugated paper board



June 21, 1932.

C. DE L. WOOD, SR

CORRUGATED PAPER BOARD Filed Sept. 29; 1950 FIG-2 luver 'roe- 'MiW AmeHEY.

Patented June 21, 1932 UNITED STATES PATENT OFFICE CHARLES DE LOBMANWOOD, 83., 01' LAKEWOOD, OHIO, ASSIGNOB TO TEE GRASSELLI CHEMICALOOMDANY, OF CLEVELAND, OHIO, A CORPORATION OF DELAWARE CORRUGATED PAPERBOARD Application filed September 29, 1930. Serial No. 485,068.

It has at various times been suggested to use multiply sheets forthefacers, or liners, of corrugated paper board, but as far as my knowledgegoes no such corrugated paper 5 boards have been very successfulcommervarious plies gives to the composition a par-' cially. This is inmy belief due to the fact that in all such instances paper of the sameconstruction has been used and except where the adhesive or bindingmaterial between the ticular advantage, such as. waterproofness, themultiply facers have substantially the same properties as a single plyboard of the same thickness. The added cost of making and using themultiply sheet does not compensate for whatever other advantages havebeen obtained in the corrugated board made from such multiply sheets.

By construction of the paper I refer to the method or type of papermachine used to provolves superimposing several layers, usually up to 6,of pulp stock, which blend into a single sheet or board: each layer mayhave incorporated in it different sizes and pulp stocks, etc., but inall layers the fibres will have substanially the same direction. Anydesired thickness of paper or even board, practically up to 0.08", oreven more, can be made directly on a cylinder machine.

The other type of paper differing in construction from cylinder paper isobtained on what is known as a Fourdrinier paper making machine. Thefibres in the-Fourdrinier paper lay in all possible directions, wherebyapaper of uniform str gt-h is obtained. The thickness of a paper whichcan be made on a Fourdrinier machine is practically limited by the speedat which sucha machine can be run economically, and it seldom exceeds0.018. Another distinguishing feature of the Fourdrinier paper is thatany size or waterproofing agent added to the paper stock will bedistributed equally and uniformly throughout the whole mass of thepaper.

My invention comprises a corrugated paper board in which one or more ofthe facers are made of a multiply sheet in which papers of a differentconstruction are combined.

My invention further contemplates the use of multiply paper of the abovetype in which the various sheets are united in a particular manner. Thisparticular type of multiply sheet is disclosed and claimed in myco-pending application, Serial No. 485,300, filed on even date herewith,and will be referred to in detail below.

A corrugated board according to my invention consists of the usualcorrugated sheet, to which is attached at its crowns a facing sheet.said facing sheet being built up of a relatively thick cylinder paperwhich gives to the board the necessary body and a relatively thinFourdrinier paper, which gives to the composition additional strength,particularly in the direction parallel to the grain of the cylinderpaper. I produce in. this manner a board of greater strength than aboard made with facers of cylinder paper only, or in other words. atequal strength across the grain of the cylinder paper, boards accordingto my invention will be lighter, thinner and have animproved strength inthe direction of the grain.

The appended figures showan embodimentof iny invention in its simplestform. 4

Figure 1 represents a greatly enlarged cut or profile through part of acorrugated board made according to my invention.

Figure 2 is an unshaded perspective view, enlarged. of a piece ofcorrugated board according to my invent-ion.

No. 1 in Figure 1 is the usual-corrugated sheet of straw, chip or otherboard. No. 2 is a board as made on a cylinder machine and the drawingshows the fibres laying substantially all in one direction. No. 3 is asheet of Fourdrinier paper and the lining in the drawing of this memberis intended to indicate that the fibres are laying in all possibledirections, parallel and across the profile of the aper. Nos. 1 and 2,and 21 and 3 are united y an adhesive shown at No. 4.

The numerals in Figure 2 designate the same members as in Figure N o. 1;a piece of the Fourdrinier sheet No. 3 is represented as being brokenaway from its bond with board N o. 2. In the board of Figure 2 bothfacing sheets are alike, and consist each of an inner cylinder board andan outer F ourdrinier sheet. The drawing is intended to show thedirection of the fibres which in the cylinder boards 2 is parallel tothe front face of the board, whereas in the side face the fibres are cutthrough at right angle. The Fourdrinier liner sheet shows the fibres inboth profiles to have the same arrangement.

I have shown in this drawing facing sheets made from one cylinder boardand one Fourdrinier sheet only, but it should be understood that myinvention is not restricted to 2-ply faces and that several sheets ofcylinder and Fourdrinier paper can be alternated to build up amultiplyfacer useful in my invention.

It should also be understood that I do not limit myself to aconstruction of corrugated boards made up of a corrugated sheet facedwith multiply liners, wherein a cylinder paper, or board, face of theliner, is attached to the crowns ofthe corrugated sheet. I might withgood results reverse the order of the different papers forming thefacers, as for instance, attach the Fourdrinier paper to .the corrugatedsheet and use a cylinder boardin the liner, and particularly when singleFourdrinier paper sheets are used, the alkalinity may work through theentire sheet and destroy the water-resistant qualities of the surface,at least at the places opposite the crowns and in many instances producean unsightly discoloration.

In a corrugated board built according to iny invention I canuse acylinder sheet composed of.weak stock, such as made from old papers,commonly known as chip stock, and

I prefer a cylinder sheet, which is substantially unsized, or slightlysized, and therefor absorbent throu hout. Silicate of soda solution whenapp ied as an adhesive to such a porous orabsorbent sheet losesimmediately part of its water by absorption into the poboard continueabsorbing some of the water of the silicate adhesive, whereby completebond is gradually obtained, the water absorbed in the sheets is finallyexpelled in the dryingprocess.

In a similar manner, when attaching a highly sized or water resistingFourdrinier paper to the above absorptive chip cylinder sheet, theabsorptive properties of the chip will prevent the migration of thewater of the silicate or other adhesive into the body of the Fourdrinierpaper, and in this manner prevent attack or decomposition of the size ofthe Fourdrinier paper and its discoloration..

In my preferred'embodiment of the invention I contemplate making themultiply liner before attaching it to the corrugated sheet. Thereby Ican apply considerably more pressure and consequently use less adhesivefor uniting the cylinder sheet to the Fourdrinier.

paper than if I should first attach the inner lining sheet to thecorrugated board and then face it with one or more liners of paper of adifferent construction.

The multiply sheet composed of one or more sheets of unsized, or partlysized, but absorbent cylinder sheets alternating with highly sized orhighly water-resistant Fourdrinier paper sheets forms the subject matterof my co-pending application referred to above. It will be understoodfrom the above description that in the preferred embodiment of myinvention I will have a multiply facer or liner, attached to the crownsof the corrugated board, said facer being composed of one or more highlysized or water-resistant Fourdrinier paper sheets and one or moreunsized or moderately sized absorbent cylinder sheets which will haveabsorbed small amounts of moisture from the water soluble adhesive,whereby action of the water from the adhesive upon the Fourdinier paperhas been substanti ally prevented, the cylinder sheets and Fourdiniersheets alternating in layers, and I also prefer to attach my facers orliners to the corru ated board in such a manner that the cylin er sheetis in contact and attached to the crowns of the corrugations.

The construction of my corrugated board is effected in the commonly usedmachines, using the ordinary adhesives for this purpose, such as sodiumsilicate,-etc. .I prefer in this construction to form the .multiplyliners first and attach said finished multiply liners to the corrugatedboard in exactly the asoa'zoa same manner as single ply liners have beenper,'which is faced by a sheet of highly sized attached previously tothe corrugated board, ourdrimer paper, the various sheets being and asthis process is well known to those oined together by an adheslve.

skilled in this art it does not need to be de- In testimony whereof, Iaifix my signature.

@ scribed in detail. CHAIES at a N woes, Sr.

It is also possible to attach first one sheet to the corrugated boardand then face this with one or more additional sheets of paper ofdifierent construction, but this latter procedure would appear to beless practical than the preferred one disclosed above, inasmuch as it isimpossible to use high pressure when uniting a facer to a corrugatedsheet without crushing the corrugations and, therefore, a considerablylarger amount of adhesive is required with the possibility of lessuniform distribution of the moisture of the adhesive throughout theabsorptive cylinder paper used in my invention.

20 The improved corrugated board made according to y invention can beused to advantage for insulating purposes, etc., but it is mainlyintended for the construction of corrugated fibre shipping containers.Containers so made will be stiffer and stronger and will still retainthe cushioning effect of the corrugated sheets. They will also resistrough handling and safely carry heavier loads than corrugated containersmade as at presout.

I claim:

1. A corrugated board comprising a corrugated sheet of paper faced witha liner consisting of sheets of paper of different construction, joinedtogether by an adhesive part of said sheets being cylinder paper, othersheets being Fourdrinier paper.

' 2. A corrugated board comprising a corrugated sheet of paper facedwith a liner comprising alternating sheets of cylinder and Fourdrinierpaper, joined together by an I adhesive.

3. A corrugated board comprising a corrugated sheet of paper faced witha liner comprising a sheet of cylinder paper and a sheet of Fourdrinierpaper, joined together by an adhesive.

4. A corrugated board comprising a corrugated sheet of paper faced witha liner comprising a sheet of substantially unsized, absorbent cylinderpaper and a sheet of high- 1y sized Fourdrinier paper, joined togetherby an adhesive.

5. A corrugated board "comprising a corrugated sheet of paper faced witha liner consisting of alternating sheets of substantially unsized,absorbent cylinder paper and sheets of highly sized Fourdrinier paper,said lining being attached by an adhesive to the crowns of thecorrugations at one of its faces consisting of a cylinder sheet.

. 6. A corrugated board comprising a corrugated sheet of paper to whichis attached 6 at the crowns of the corrugations a sheet of substantiallyunsized, absorbent cylinder pa-

